Fatty chemical polyalcohols as reagent thinners

ABSTRACT

A process for producing coating compositions involving: (a) providing a reactive diluent, (b) providing an inert solvent, (c) providing a polymeric polyol, (d) providing an isocyanate, (e) reacting (a)-(d) in a reactive diluent comprising a ring opening product of a carboxylic acid ester epoxide with a dihycric or higher alcohol.

FIELD OF THE INVENTION

This invention relates to the use of oleochemical polyols as reactivediluents in coating compositions. The use of such dilution systemsresults in a saving of up to 60% of solvent in high-solids polyurethanesystems.

BACKGROUND OF THE INVENTION

Polyurethanes may be used in various forms including, for example,elastomers, foams, casting resins, composite materials, paints and othercoatings. Polyurethane-based products such as these are normallyproduced by reacting aliphatic, aromatic and even heterocyclicisocyanates with high molecular weight polymers containing hydroxygroups. The properties of the resulting polyurethanes are largelydetermined by the nature and mixing ratio of the basic monomers and byany additives present. One of the most important applications ofpolyurethanes is in the field of coating compositions. Polyurethanefilms exhibit, for example, good substrate adhesion, gloss, electricallyinsulating properties, low gas permeability, resistance to water andsolvents and high resistance to weathering. In addition, they can beproduced with different degrees of flexibility and under varioustemperature conditions.

In general, any polyhydroxy compound may be used together with acomponent containing at least two isocyanate groups for the productionof polyurethanes. Hydroxyl-terminated polyesters with or withoutadditional hydroxy groups on the polymer chain, hydroxyl-terminatedpolyethers, copolymers of hydroxyl-functionalized acrylates and/ormethacrylates with acrylate and/or methacrylate esters, styrene,copolymers of allyl alcohol and other unsaturated monomers and alsoalkyd resins are preferably used as the polymeric polyols.Unfortunately, hydroxy-functional polymers such as these are highlyviscous resins and require solvents, in some cases considerablequantities of solvents, to obtain a viscosity suitable for applicationthrough spray nozzles.

One way of reducing the viscosity of coating compositions containinghigh molecular weight resins is to mix the polymeric polyols with lowmolecular weight, hydroxyl-terminated low-viscosity polyethers. However,the disadvantage of this is that the polyurethanes formed exhibit lowhydrolysis stability, high sensitivity to solvents and poor weatheringbehavior. Another way of reducing the viscosity of a coating compositionis to use low molecular weight isocyanates as reactants for thepolymeric polyols. Unfortunately, the volatility and toxicity of thesecompounds can lead to serious environmental problems and to healthproblems for people involved in their processing. The stringent safetyprecautions involved make this method of reducing viscosityuneconomical.

Accordingly, most commercially obtainable isocyanates are reactionproducts of low molecular weight polyols with polyisocyanate compoundsin which the volatility of the isocyanate component is reduced by thehigh molecular weight of the reaction products with the polyols. Adisadvantage of the relatively high molecular weight isocyanatesdescribed herein is that, in admixture with the polymeric polyols, theirviscosity is only slightly reduced so that they are not easy to apply,for example through spray nozzles. As a result, solvent again has to beadded in a considerable quantity to reduce the viscosity of the coatingcomposition to a level suitable for application.

One method of using reactive solvents is to mix low molecular weightdiols, for example ethylene glycol, propylene glycol, glycerol andtrimethylol propane (TMP) or liquid oligomers thereof, with the coatingcomposition. Unfortunately, the use of low molecular weight reactivesolvents as chain extenders for the isocyanate component often leads tofragile, hydrolysis-sensitive polyurethane films which are generallyunable to satisfy the performance requirements for modern materials.Problems can also be caused by the incompatibility of mostpolyisocyanate components with the low molecular weight polyols whichoften leads to phase separation and hence to inadequacies in thematerial produced.

To reduce the amount of solvent in polyurethane-based coatingcompositions, it is possible for example to use low-viscosityhydrophobic polyols which, on curing of the coating composition, becomepart of the coating and thus reduce solvent emission.

CA 850,672 describes the use of oleochemical polyols for reducingviscosity in polyurethane-based coating compositions. In this case, thepartial incompatibility of the oleochemical polyols with theOH-functionalized polymers is overcome by heating the components at 250°C. The possibility of mixing the coating composition with inert solventsto reduce solvent consumption and to improve the compatibility of thereactants is not mentioned.

U.S. Pat. No. 4,535,142 describes the use of ester-linked diricinoleatederivatives as reactive diluents in high-solids coatings. One of thedisadvantages involved in such an application is, for example, thedependence on a single raw material. Another disadvantage is that,because ricinoleic acid is used, the number of OH groups can only bevaried at considerable cost, if at all.

The problem addressed by the present invention was to provide a reactivediluent which would enable the consumption of conventional solventsinert to isocyanate groups to be reduced, in general distinctly reduced.Another problem addressed by the invention was to enable the reactivediluent to be used together with other solvents in such a way that thecomponents would be compatible with no need for an additional thermalhomogenization step and all the required components would behomogeneously miscible. Another problem addressed by the invention wasto provide a polyurethane-based coating composition and a process forits production.

It has now surprisingly been found that up to 60% by weight of solventcan be saved by using ring opening products of carboxylic acid esterepoxides with dihydric or higher alcohols as reactive diluents in suchcoating compositions.

DESCRIPTION OF THE INVENTION

The present invention relates to the use of ring opening products ofcarboxylic acid ester epoxides with dihydric or higher alcohols inadmixture with polymeric polyols, isocyanates, inert solvents and,optionally, typical additives as reactive diluents for the production ofcoating compositions.

Starting materials for the reactive diluents according to the inventionare carboxylic acid esters, carboxylic acid esters of aliphatic orcycloaliphatic carboxylic acids containing 6 to 44 carbon atoms beingpreferred. Since the carboxylic acid esters are intended to be subjectedto epoxidation in a following step, one or more C—C double bonds areadvantageously already present in the carboxylic acid. However, it isalso possible in accordance with the invention to use carboxylic acidsof which the C—C double bond first has to be produced synthetically by achemical transformation such as, for example, elimination or synthesisof a C—C double bond.

Preferred carboxylic acid ester epoxides are those which can be producedfrom fatty acids and/or fatty acid esters, more particularly from fattyacids and/or fatty acid esters or derivatives of fatty acids and/orfatty acid esters of natural origin.

These include, for example, the triglycerides beef tallow, palm oil,peanut oil, castor oil, rapeseed oil, cottonseed oil, soybean oil, trainoil, sesame oil, sunflower oil, corn oil, poppyseed oil, perilla oil,cereal seed oil and linseed oil and also tall oil fatty acids and estersthereof.

The fatty acid esters may be obtained both by direct esterification ofthe fatty acid with the desired alcohol and by transesterification offatty acid esters of monohydric or polyhydric alcohols.

Aliphatic alcohols are generally used for the transesterification, thealcohols normally having a functionality of 1 to 10. Alcohols with afunctionality of 1 to 5 are preferably used, alcohols with afunctionality of 1 to 2 being particularly preferred for the purposes ofthe invention. It does not matter whether the alcohol used for thetransesterification is linear, branched, saturated or unsaturated.However, saturated alcohols containing 1 to 24 carbon atoms arepreferably used for the transesterification.

These include, for example, methanol, ethanol, propanol, isobutanol,n-butanol, hexanol, heptanol, octanol, nonanol, decanol, 2-ethylhexanol,ethylene glycol, propylene glycol and butylene glycol.

Of these alcohols, those containing 1 to 10 carbon atoms are preferredwhile those containing 1 to 3 carbon atoms are most particularlypreferred. According to the invention, the use of methanol isparticularly preferred. The unsaturated ester is reacted to form theepoxide in known manner, for example by reaction with formic acid/H₂O₂However, any other process which leads to an epoxide of an unsaturatedfatty acid ester may also be used.

The epoxidation reaction is preferably carried out quantitatively, i.e.until all the olefinic C—C double bonds present have been reacted, ingeneral completely reacted.

Aliphatic alcohols containing 2 to 44 carbon atoms and preferably 2 to 6carbon atoms and having a functionality of 1 to 6, preferably 2 to 4and, more preferably, 2 or 3 are used for opening the oxirane ring.Examples of such alcohols are ethylene glycol, propylene glycol,butylene glycol, glycerol and trimethylol propane (TMP) and alkoxylationproducts thereof with ethylene oxide (EO), propylene oxide (PO) andEO/PO mixtures. The ring opening reaction takes place under theconditions described, for example, in DE-A-32 46 612. Suitable acidiccatalysts are typical mineral acids or lower organic carboxylic acidssuch as, for example, sulfuric acid, phosphoric acid, formic acid,trifluoromethane sulfonic acid or acetic acid. The acidic catalysts maybe used in concentrations of 0.1% by weight, based on the startingmaterials.

The ring opening reaction may be carried out at temperatures of 80 to120° C. and preferably at temperatures of 90 to 100° C. The catalystacid is then advantageously neutralized with a base, for example withsodium hydroxide, sodium methylate or tertiary amines.

The ratio of OH groups to oxirane rings is generally between 5:1 and 1:5and preferably between 2:1 and 1:2, a ratio of 1.4:1 to 1:1.4 beingparticularly preferred for the purposes of the invention. Carboxylicacid ester epoxides containing a C₈₋₂₄ fatty acid residue are preferablyring-opened, the use of carboxylic acid ester epoxides containing 14 to18 carbon atoms generally being preferred for the purposes of theinvention.

The reactive diluents thus obtainable generally have an OH value of 30to 800, OH values of 120 to 550 being preferred. The epoxide valueshould not exceed 9.5 and is generally between 0 and 5.5, epoxide valuesof 0 to 2.5 being particularly preferred. Normally, the polyols thusobtained are largely water-free, a water content of less than 0.5% byweight being preferred and a water content of less than 0.1% by weightbeing particularly preferred for the purposes of the invention.

The reactive diluents generally have an OH equivalent weight of lessthan 320, their molecular weight generally not exceeding 5,000 andpreferably not exceeding 3,000.

In the context of the invention, the equivalent weight is understood tobe the molecular weight divided by the number of OH groups.

Besides the reactive diluents, the coating composition containspolymeric polyols as resins. In the context of the present invention, aresin is normally understood to be a material which—generally togetherwith a corresponding hardener—represents a binder which forms amacromolecular network with the requisite material properties,preferably by chemical reaction.

Polyester polyols, alkyd resins, hydroxyl-containing polyacrylatesand/or polymethacrylates may generally be used as polymeric polyols forthe purposes of the invention. It is also possible to use polymersand/or copolymers obtained by polymerization, polyaddition orpolycondensation of hydroxyl-containing monomers or (co)polymers fromwhich hydroxy groups can be released in a subsequent polymer-analogreaction. Products of the addition of one or more moles of ethyleneoxide, propylene oxide and/or higher alkylene oxides to at leastdihydric alcohols are also polymeric polyols in the context of thepresent invention.

According to the invention, polyester polyols and polyether polyols ormixtures thereof, alkyd resins, hydroxyfunctional polyacrylates andpolymethacrylates are used as polymeric polyols.

It is particularly preferred to use polyester polyols obtained bycondensation of difunctional aliphatic and/or aromatic acids withpolyhydric aliphatic alcohols, more particularly from the condensationof phthalic acid and TMP. Among the hydroxyfunctionalpoly(meth)acrylates, those with an average to high degree ofcrosslinking are preferred for the purposes of the invention.

The polymeric polyols generally have an equivalent weight of more than320, their molecular weight preferably being higher than 1,500 and, morepreferably, higher than 3,000. The polymeric polyols may be present insolid or liquid form. So far as the invention is concerned, it does notmatter whether the polymer has first to be converted into the liquidaggregate state by addition of solvent or by heating or whether it isinherently liquid.

In addition, other solvents than the polyols obtained by ring opening ofcarboxylic acid ester epoxides may be used in the coating compositionsaccording to the invention. Any incompatibility between resin, hardenerand reactive diluent and additives, if any, can lead to phaseseparation, clouding and, hence, inferior material properties. Besidesreducing viscosity, the addition of other solvents can overcome anyincompatibility between the individual components of the coatingcomposition. The percentage content of these “inert” solvents will bedetermined by the desired viscosity and by the desired homogeneity ofthe coating composition. Their contribution to the overall diluentcontent (consisting of reactive diluent and other solvents) may amountto between 1 and 99% by weight, but is preferably between 1 and 80% byweight and more preferably between 1 and 60% by weight. According to theinvention, solvents which are substantially or completely inert toisocyanate groups are preferably used. They are generally addedirrespective of the presence of other solvents in one of the componentsof the coating composition. The solvent is preferably used in a quantityof at least 1% by weight, based on the total solvent and reactivediluent content.

In a particularly preferred embodiment, solvents completely inert toisocyanate groups are selected from the group consisting of xylenes,toluene and higher alkyl benzenes, such as ethyl benzene and propylbenzene, esters such as, for example, methoxypropyl acetate,ethoxypropyl acetate and 2-methoxy-1-methyl acetate and low molecularweight ketones.

The coating composition according to the invention additionally containspolyisocyanates as hardeners. As well-known to the expert, isocyanatesreact with free hydroxy groups in an addition reaction to form aurethane group. Any of the usual polyfunctional aromatic and aliphaticisocyanates including, for example, any oligomeric and polymericisocyanate compounds of the type obtainable by oligomerization orcyclization of polyisocyanates in the absence of moisture or by reactionof polyhydric alcohols with polyisocyanates may generally be used as theisocyanate components according to the invention. The polyisocyanatesmay be used in more than and less than the equivalent quantities.Examples include HDI trimer (tris-(6-isocyanatohexyl)-isocyanurate)(Tolonate® HDT, Rhone-Poulenc), 4,4-diphenyl methane diisocyanate (MDI)(Desmodur® VL, Bayer AG), HDI biuret(1,3,5-tris-(6-isocyanatohexyl)-biuret), hexamethylene diisocyanatebiuret (Desmoduro® N 75, Bayer AG) and an aromatic polyisocyanate basedon toluylene diisocyanate (Desmodur® L 67, Bayer AG). The hardener isadded in such a quantity that the OH:NCO equivalence ratio is between1:0.1 and 1:1.5, preferably between 1:0.75 and 1:1.25 and morepreferably between 1:0.9 and 1:1.1.

The isocyanates may be used both in pure form and in the form oftechnical mixtures with or without solvent.

Other components of the coating compositions are—optionally—additivessuch as, for example, dyes, pigments, fillers, rheological additives,antioxidants, bactericides, fungicides, corrosion inhibitors, catalystsand UV stabilizers.

The present invention also relates to a process for the production ofpolyurethane-based coating compositions in which ring opening productsof carboxylic acid ester epoxides with dihydric or higher alcohols asreactive diluents, inert solvents, polymeric polyols and optionallytypical additives are mixed with isocyanates.

More particularly, the invention relates to a process for the productionof polyurethane-based coating compositions in which ring openingproducts of carboxylic acid ester epoxides with dihydric or higheralcohols as reactive diluents are mixed with inert solvents, polymericpolyols and optionally typical additives.

The invention also relates to coating compositions containing ringopening products of carboxylic acid ester epoxides with dihydric orhigher alcohols as reactive diluents, inert solvents, polymeric polyols,isocyanates and optionally typical additives.

According to the invention, coating compositions which contain thereactive diluent in a quantity of 1 to 99% by weight, based on the totaldiluent content, and the inert solvents in a quantity of 1 to 99% byweight and preferably 1 to 50% by weight, based on the total diluentcontent, are generally preferred.

EXAMPLES

Various oleochemical polyols were tested for their suitability asreactive diluents in clear lacquers and finishing lacquers. The tradename is followed in brackets by the abbreviations used in the Examples.

The following Henkel products were used as the oleochemical polyols:

Sovermol® 750 (750), Sovermol® 815 (815) and Sovermol® 1102/I (1102)

These oleochemical polyols are branched polyesters/polyethers based onoleochemicals.

The following Bayer products were used as the polyester polyols:

Desmophen ® 650 (650) branched hydroxyl-containing polyester Desmophen ®651 (651) branched hydroxyl-containing polyester Desmophen ® 670 (670)lightly branched hydroxl-containing polyester Alkydal ® R 35 (R 35)alkyd resin containing 38% ricinene oil

The following products of Henkel Corp. were used as thehydroxyl-containing polyacrylates:

G-Cure ® 105 (105) hydroxyl-containing polyacrylate with a low toaverage crosslink density G-Cure ® 106 (106) hydroxyl-containingpolyacrylate with an average crosslink density G-Cure ® 109 (109)hydroxyl-containing polyacrylate with a high crosslink density

The following isocyanates were used for crosslinking:

Desmodur ® L 67 (L 67) aromatic polyisocyanate based on toluylenediisocyanate Desmodur ® N 75 (N 75) hexamethylene-1,6-diisocyanatobiruetDesmodur ® VL (VL) 4,4′-diphenyl methane diisocyanate Tolonate ® HDT(HDT) tris-(6-isocyanatohexyl)-isocyanurate (trimer) Tolonate ® HDT-LV(HDT-LV) low-viscosity preparation of tris-(6-isocyanatohexyl)-isocyanurate (trimer)

The weathering tests were carried out in a QUV accelerated weatheringtester, ASTM G 53-77, for artificial weathering. The exposure toultraviolet light was carried out at 350 nm. The test conditions were 4hours' light at 60° C. and 4 hours' condensation at 50° C.

The viscosities were measured with a Brookfield viscosimeter, spindle 4,at 25° C./30 r.p.m.

The pendulum hardness values were measured in accordance with DIN 53157.

Clear Lacquers I

Table 1 below illustrates the effectiveness of the polyols according tothe invention when used with polyester polyols in clear lacquers. Theparticular polyester polyol is shown in the column headed “Polyol”. Thecolumn headed “Isocyanate” is self-explanatory. The viscosity of themixture of the corresponding polyol with the corresponding isocyanate isshown in the column headed “Initial visc.”. The quantity ofxylene/methoxypropyl acetate (3:1) in % by weight, based on the coatingcomposition as a whole, which is required to achieve a viscosity of1,000 mPas in the coating composition is shown in the column headed“Solv. for 1,000 mpas”. Then come three headings “Polyol 750”, “Polyol815” and “Polyol 1102” each covering three columns. The “+20%” columnshows the viscosity of the coating composition after an addition of 20%by weight (based on the coating composition as a whole) of theparticular oleochemical polyol. The “% Solv.” column shows the quantityof xylene/methoxypropyl acetate (3:1) which is required to achieve aviscosity of 1,000 mPas after addition of the reactive diluent while the“Δ” column shows the difference in quantity (in parts by weight) for theaddition of xylene/methoxypropyl acetate (3:1) for achieving a viscosityof 1,000 mPas without and with oleochemical polyol as reactive diluent.

It can clearly be seen that, in virtually every case, the use of 20% byweight of the ring-opened oleochemical polyols in accordance with theinvention leads to a distinct reduction in the consumption of solventrequired to reach an exemplary application viscosity of 1,000 mPas. Theapplication viscosity of 1,000 mPas selected in the Examples is notintended to limit the invention in any way and, if desired, may becorrected both upwards and downwards in known manner by varying thecomponents.

Clear Lacquers II

Table 2 illustrates the effectiveness of the polyols according to theinvention when used with hydroxyl-containing polyacrylates in clearlacquers. The particular polyacrylate is shown in the column headed“Polyol”. The other column headings have the same meanings as in Table1.

Table 3 compares the pendulum hardnesses (as measured in accordance withDIN 53157) of the clear lacquers according to the invention with thependulum hardnesses of conventionally produced coating compositions.

Finishing Lacquers I

Table 4 compares the strengths of the finishing lacquers according tothe invention with those of conventional coating compositions. Polyesterpolyols were used as the polymeric polyol. The combinationspolyol/reactive diluent and isocyanate are shown in the uppermost line.The following lines represent the behavior of finishing lacquersaccording to the invention and comparison finishing lacquers in a QUVaccelerated weathering tester. Resistance to methyl ethyl ketone isshown in the last line.

The test results show that the use of the reactive diluents inaccordance with the invention in various amounts with polyester polyolsproduces improved results, in some cases distinctly improved results, inregard to the hardness and gloss of the products obtained. Weathering inthe QUV accelerated weathering tester shows that the weatheringresistance of coatings produced using reactive diluents are almostidentical with the values of comparison coatings.

Table 5 shows the results of tests identical with Table 4 usinghydroxyl-containing polyacrylates as the polymeric polyols.

TABLE 1 Saving of Solvent in Clear Lacquers (Polyurethane) ContainingReactive Diluent Initial % Solv. for Reactive diluent 750 PolyolIsocyanate visc. 1000 mPas +20% % Solv. Δ 650 N 75 2400 8.8 2000 4.8−4.0 L 67 6100 13.3 5100 9.6 −3.7 651 N 75 2300 3.9 1500 2.0 −1.9 L 677600 13.9 4100 7.4 −6.5 670 N 75 1000 — 950 — 0 L 67 2200 8.0 1900 4.6−3.4 VL 1850 2.2 1800 6.1 +3.9 HDT 3000 9.6 2300 9.6 0 HDT-LV 2400 7.11600 5.9 −1.2 R 35 N 75 980 — 600 — — L 67 1710 5.5 1200 — −5.5 VL 1040— 700 — — HDT 1610 8.1 1100 — −8.1 HDT-LV 1130 — 750 — — Reactivediluent 815 Reactive diluent 1102 Polyol Isocyanate +20% % Solv. Δ +20%% Solv. Δ 650 N 75 2300 4.7 −4.1 2200 4.2 −4.6 L 67 5200 11.5 −1.8 425011.6 −1.7 651 N 75 — — — 1600 7.0 −1.9 L 67 — — — 4300 8.6 −5.3 670 N 75950 — 0 850 — 0 L 67 1900 4.5 −3.5 1600 4.3 −3.7 VL 1800 6.3 +4.1 15006.3 +4.1 HDT 2300 9.9 −0.3 2000 9.9 +0.3 HDT-LV 1600 5.7 −1.4 1500 5.8−1.3 R 35 N 75 700 — 0 550 — — L 67 1540 — −5.5 1100 — −5.5 VL 900 — 0650 — — HDT 1500 — −8.1 950 — −8.1 HDT-LV 950 — — 800 — —

TABLE 2 Saving of Solvent in Clear Lacquers (Acrylates) ContainingReactive Diluent Initial % Solv. for Reactive diluent 750 PolyolIsocyanate visc. 1000 mPas +20% % Solv. Δ G 105 N 75 4500 10.1 1900 3.8−6.3 L 67 10250 17.1 4300 10.6 −6.5 VL 10800 13.8 5350 12.5 −1.3 HDT17000 18.7 7800 16.9 −1.8 HDT-LV 13600 16.9 4750 16.6 −0.3 G 106 N 751500 2.0 1000 — −2.0 L 67 3350 8.2 2600 5.1 −3.1 VL 3500 7.4 2300 6.0−1.4 HDT 5900 13.0 4000 8.9 −4.1 HDT-LV 3750 6.8 2800 5.3 −1.5 G 109 N75 1900 4.0 1200 — −4.0 L 67 7600 10.4 3650 7.9 −2.5 VL 6000 11.4 37008.9 −2.5 HDT 10100 14.8 5950 11.5 −3.3 HDT-LV 6700 11.7 3750 7.9 −3.8Reactive diluent 815 Reactive diluent 1102 Polyol Isocyanate +20% %Solv. Δ +20% % Solv. Δ G 105 N 75 2400 5.9 −4.2 1900 4.0 −6.1 L 67 535012.3 −4.8 4250 10.8 −6.3 VL 6100 13.1 −0.7 5300 12.2 −1.6 HDT 8850 17.6−1.1 7500 15.8 −2.9 HDT-LV 6150 16.5 −0.4 4600 15.2 −1.7 G 106 N 75 1100— −2.0 900 — −2.0 L 67 3000 7.4 −0.8 2400 5.0 −3.2 VL 2700 6.0 −1.4 21005.9 −1.5 HDT 4100 10.2 −2.8 3800 8.3 −4.7 HDT-LV 3100 6.3 −0.5 2650 5.0−1.8 G 109 N 75 1300 1.0 −3.0 1000 — −4.0 L 67 3850 7.7 −2.7 3400 6.0−4.4 VL 3950 10.1 −1.3 3500 7.2 −4.2 HDT 6100 12.4 −2.4 5750 10.2 −4.6HDT-LV 3900 8.2 −3.5 3600 6.5 −5.2

TABLE 3 Comparison of the Pendulum Hardness Values (DIN 53157) of ClearLacquers Containing Reactive Diluent With no addition With 20% 750Polyol Isocyanate Beginning End Beginning End D 650 N 75 14 207 <14 213L 67 83 179 130 190 D 651 N 75 80 216 17 207 L 67 157 178 161 186 D 670N 75 <14 <14 <14 25 L 67 38 55 32 104 VL 14 22 15 32 HDT <14 <14 <14 29HDT-LV <14 <14 <14 17 Alkydal R 35 N 75 46 199 20 92 L 67 119 185 129169 VL 100 130 115 150 HDT 52 146 21 92 HDT-LV 39 133 17 64 G-Cure 105 N75 21 203 <14 136 L 67 104 158 101 154 VL 143 157 123 147 HDT 22 200 <14171 HDT-LV <14 193 <14 169 G-Cure 106 N 75 17 181 <14 157 L 67 130 164120 165 VL 158 162 146 146 HDT 31 193 <14 179 HDT-LV 22 189 <14 179G-Cure 109 N 75 <14 200 <14 188 L 67 101 174 102 165 VL 48 168 139 158HDT <4 195 <14 174 HDT-LV <14 196 <14 171 With 20% 815 With 20% 1102Polyol Isocyanate Beginning End Beginning End D 650 N 75 <14 219 <14 217L 67 119 190 98 182 D 651 N 75 — — 15 175 L 67 — — 158 183 D 670 N 75<14 24 <14 20 L 67 21 52 25 84 VL <14 34 <14 120 HDT <14 15 <14 15HDT-LV <14 <14 <14 <14 Alkydal R 35 N 75 22 76 <14 64 L 67 99 160 108169 VL 80 110 126 137 HDT 22 84 14 64 HDT-LV 21 78 <14 57 G-Cure 105 N75 <14 150 <14 111 L 67 99 155 78 143 VL 132 148 126 143 HDT <14 169 <14148 HDT-LV <14 155 <14 139 G-Cure 106 N 75 <14 165 <14 155 L 67 116 17199 157 VL 136 152 134 149 HDT <14 181 <14 177 HDT-LV <14 175 <14 175G-Cure 109 N 75 <14 175 <14 167 L 67 106 168 91 168 VL 118 143 146 167HDT <14 185 <14 160 HDT-LV <14 181 <14 164

TABLE 4 Comparison of the Strengths of Finishing Lacquers (Polyester)Polyol/reactive diluent D 650 D 650/750 651 651/750 Isocyanate N 75 N 75N 75 N 75 Spraying viscosity 40-80 secs., 34.0 27.0 27.3 21.2 % solv. %Solids 66.0 73.0 72.7 78.8 Gloss 53 88 86 86 Whiteness after h QUVBeginning 86.0 87.5 85.8 84.9 500 h 75.5 79.8 79.2 78.1 Gloss after hQUV Beginning 56 92 90 90 500 h 9 29 66 49 MEK >1 h >1 h >1 h ˜1 hPolyol/reactive diluent 670 670/750 670 670/750 Isocyanate N 75 N 75HDT-LV HDT-LV Spraying viscosity 40-80 22.0 24.5 19.6 16.6 secs., %solv. % Solids 78.0 75.5 80.4 83.4 Gloss — — — — Whiteness after h QUVBeginning 86.2 87.9 87.3 87.4 500 h 76.5 76.6 77.4 78.7 Gloss after hQUV Beginning n.m. n.m. n.m. n.m. 500 h n.m. n.m. n.m. n.m. MEK <1 Min.<1 Min. <1 Min. <1 Min.

TABLE 5 Comparison of the Strengths of Finishing Lacquers (Acrylates)Polyol G 105/750 G 105/750 G 105 G 105/750 Isocyanate N 75 N 75 HDT-LVHDT-LV % Solv. at spraying visc. 50-100 secs. 32.7 29.7 30.3 25.5 %Solids 67.3 70.3 69.7 74.5 Whiteness after h QUV Beginning 89.7 85.187.9 83.9 500 h 81.7 77.8 82.3 77.9 MEK ˜1 min. ˜1 min. ˜1 min. ˜1 min.Polyol G 106 G 106/750 G 106 G 106/750 Isocyanate N 75 N 75 HDT-LVHDT-LV % Solv. at spraying visc. 50-100 secs. 28.4 27.0 25.3 22.5 %Solids 71.6 73.0 74.7 77.5 Whiteness after h QUV Beginning 89.2 85.988.4 85.8 500 h 85.2 81.8 84.5 81.6 MEK ˜5 mins. ˜1 min. ˜1 min. ˜min.Polyol G 109 G 109/750 G 109 G 109/750 Isocyanate N 75 N 75 HDT-LVHDT-LV % Solv. at spraying visc. 50-100 secs. 28.0 27.8 24.9 23.7 %Solids 72.0 72.2 75.1 76.3 Whiteness after h QUV Beginning 87.9 85.689.4 84.6 500 h 81.7 80.8 82.2 80.9 MEK ˜5 mins. ˜5 mins. ˜5 mins. ˜1min.

What is claimed is:
 1. A process for producing coating compositionscomprising: (a) providing a reactive diluent, (b) providing an inertsolvent, (c) providing a polymeric polyol, (d) providing an isocyanate,(e) reacting (a)-(d) in a reactive diluent comprising a ring openingproduct of a carboxylic acid ester epoxide with a dihydric or higheralcohol.
 2. The improved process of claim 1, wherein said carboxylicacid ester epoxide is selected from the group consisting of epoxide offatty acid, epoxide of fatty acid ester and mixtures thereof.
 3. Theimproved process of claim 1, wherein said carboxylic acid ester epoxideis selected from the group consisting of epoxide of fatty acid ofnatural origin, epoxide of fatty acid ester of natural origin andmixtures thereof.
 4. The improved process of claim 1, wherein saidcarboxylic acid ester epoxide comprises a C₆₋₂₄ fatty acid residue. 5.The improved process of claim 1, wherein said polymeric polyol isselected from the group consisting of polyester polyol, polyetherpolyol, alkyd resin, hydroxyl-containing polyacrylate,hydroxyl-containing polymethacrylate and mixtures thereof.
 6. Theimproved process of claim 1, wherein said inert solvent is present in aquantity of about 1 to about 99% by weight, based on the total solventand reactive diluent content.
 7. The improved process of claim 1,wherein said inert solvent is selected from the group consisting ofxylene, toluene, methoxypropyl acetate, ethoxypropyl acetate, ethylbenzene, propyl benzene, 2-methoxy-1-methyl ethyl acetate and mixturesthereof.
 8. A process for the production of polyurethane-based coatingcompositions, comprising the step of mixing: polyol; inert solvent; aring opening product of combining carboxylic acid ester epoxide withdihydric or higher alcohol as a reactive diluent; and isocyanate. 9.Coating compositions comprising: a ring opening product of combiningcarboxylic acid ester epoxide with dihydric or higher alcohol as areactive diluent; polymeric polyol; inert solvent; and isocyanate. 10.The composition of claim 9, wherein said carboxylic acid ester epoxideis selected from the group consisting of epoxide of fatty acid, epoxideof fatty acid ester and mixtures thereof.
 11. The composition of claim9, wherein said carboxylic acid ester epoxide is selected from the groupconsisting of epoxide of fatty acid of natural origin, epoxide of fattyacid ester of natural origin and mixtures thereof.
 12. The compositionof claim 9, wherein said carboxylic acid ester epoxide is selected fromthe group consisting of epoxide of beef tallow, epoxide of palm oil,epoxide of peanut oil, epoxide of castor oil, epoxide of rapeseed oil,epoxide of cottonseed oil, epoxide of soybean oil, epoxide of train oil,epoxide of sesame oil, epoxide of sunflower oil, epoxide of corn oil,epoxide of poppyseed oil, epoxide of perilla oil, epoxide of cereal seedoil, epoxide of linseed oil, epoxide of tall oil fatty acid ester andmixtures thereof.
 13. The composition of claim 9, wherein saidcarboxylic acid ester epoxides comprise a C₆₋₂₄ fatty acid residue. 14.The composition of claim 9, wherein said higher alcohol is an aliphaticalcohol comprising about 2 to about 44 carbon atoms and has afunctionality of about 1 to about
 6. 15. The composition of claim 9,wherein said dihydric or higher alcohol is an aliphatic alcoholcomprising about 2 to about 6 carbon atoms and has a functionality ofabout 2 to about
 4. 16. The composition of claim 9, wherein saiddihydric or higher alcohol is selected from the group consisting ofethylene glycol, propylene glycol, butylene glycol, glycerol,trimethylol propane and alkoxylation products thereof with ethyleneoxide, propylene oxide and ethylene oxide/propylene oxide mixtures andmixtures thereof.
 17. The composition of claim 9, wherein the ratio ofthe OH groups of said dihydric or higher alcohol to the oxirane rings ofsaid carboxylic acid ester epoxide is between about 5:1 and about 1:5.18. The composition of claim 9, wherein the ratio of the OH groups ofsaid dihydric or higher alcohol to the oxirane rings of said carboxylicacid ester epoxide is between about 2:1 and about 1:2.
 19. Thecomposition of claim 9, wherein the ratio of the OH groups of saiddihydric or higher alcohol to the oxirane rings of said carboxylic acidester epoxide is between about 1.4:1 to about 1:1.4.
 20. The compositionof claim 9, wherein the reactive diluent has an OH value of about 30 toabout
 800. 21. The composition of claim 9, wherein the reactive diluenthas an OH value of about 120 to about
 550. 22. The compostion of claim9, wherein the reactive diluent has an epoxide value of up to about 9.5.23. The composition of claim 9, wherein the reactive diluent has anepoxide value of up to about 5.5.
 24. The composition of claim 9,wherein the reactive diluent has an epoxide value of up to about 2.5.